Grinding mill



May 9, 1933.

O. N. GREDELL GRINDING MILL Filed Sept. 4, 1931 INVENTOR. Of/o A4 Grads/A A TTORNE Y.

Patented May 9, 1933 UNITED STATES PATENT OFFICE- o'rro N. GREDELL, or KANSAS CITY, ivrrssounr, ASSIG-NOB r s'rANnAIm srnnr. wonxs;

or' Non'rIrxANsAs crrY, MISSOURI, A CORPORATION or MISSOURI GRINDING MILL Application filed September 4,- 1931. Serial No. 561,172..

This invention relates to grinding mills and more particularly to those of that character wherein the material to be ground is initiallycut and then reduced by action of revolving hammers or the like. i

The principal objects of the invention are to provide a grinder of: this character which has greater capacity, grinds faster and feeds freer than those now in use.

It is also an important object to provide a grinder particularly adapted to handle coarse commodities such. as corn fodder, hay, alfalfa and the like.

In accomplishing these and other objects of the invention I have provided improved details of structure, the preferred form 'of which is illustrated in the accompanying drawing wherein: i

Fig. 1 is a vertical sectional View of a grinder embodying the present invention.

Fig. 2 is a cross sectional view through the grinder on the line 2+2, Fig.1. 7 p

Fig. 3 is a detail perspective view. of the rotorshowing the cutter knife and the hammer elements at one end of therotor removed to better. illustrate their mounting.

Fig. 4c is a sectional view through the rotor illustrating the method of securing the cutter knives, and

Fig. 5 is a similar view through the pivot mounting of one of the hammers. V

Referring more in detail to the drawing:

1 designates the grindercasing which includes vertical side plates 2 and 3 spaced apart by an arcuate band 4 to form a sub. stantially cylindrical rotor chamber 5. The ends 6 and 7 of the band terminate short of each other to form a radial discharge outlet 8 for the material reduced inthe chamber5 which is discharged therefrom. into an exhaust chamber. 9. I

The exhaust chamber is defined by up.- Wardextensions of the side plates 2 and 3 and by spaced plates 10 and 11 positioned therebetween at adjacent ends of the dis charge outlet. The lower ends of the plates 10 and 11 are preferably spaced from the ends of the band tov form shoulders .12 and 13 to support a screen member 14 and their upper ends cooperate with the side plates to effect a balance.

to connect a discharge conduit 15 through?- which reduced material. is conveyed from 1 the exhaust chamber. y

The screen 14 is preferably formed from. a'perforated plate curved to conform to the radius of the rotor chamber and is of suffi cient length so that its ends will engage against the shoulders .12 and 13 as shown in.Fig.1. V 1 The band4c,'plates10 and Hand the'screen 1 1 may beclamped between the. side plates by suitable bolts 16 and selected b oltsmay pass through angle shaped loops 17 welded to the outer faces of saidmembers.

The side plate 2 is provided witha rec tangular shaped inlet opening 18 preferably positioned between the axis of the'rotor housing and its periphery through which material is fed intothe rotor chamber as later described. y V I Rotatably mounted in suitable bearings 19: and 20 carried bythe side plates is a shaft 21 adapted to be operated "bya pulley 22 mounted on. a projecting end .thereoffas shown in Fig.2. i

by a spline 23 is a rotor 24consist ing of a hub portion 25 having radial arms 26 and 27 projecting from its end adjacent the plate 2 and'from the opposite sides thereof v 76 Keyed to the shaft Within the chamberb 4 Extending from the side faces of the arms adjacentthe side plate 2 are pairs of pref! erably cylindrical bosses 28 and 29 having openings 30 extending axially therethrough and through the arms.

Supported bygthe bosses are cutter blades saf 31 and 32 comprising rectangular shaped steel barslhaving longitudinal cutting edges 33 on the sides of the bars in the direction 32 are provided with sockets34 of suitable .90 of rotation; of the rotor. The blades 31Iand size and shape to accommodate the. endsof 1 the bosses and have openings 35 aligning with the. openings in the, rotor arms. The ends of the openings 35:31] the front face of theblades arepreferably countersunk to ac-Y commodate the fiat heads of bolts 36, the

bolts having threaded shanks 37 whichjare pr i eted hwus he Openings 39 e ms nuts 38 by which the blades are drawn tightly against the ends of the bosses. In order to prevent rotation of the bolts in manipulating the nuts, the heads are preferably provided with tongues 39 which engage in recesses 40 formed in the faces of the blades as best illustrated in Fig. 3.

It is apparent that by mounting the ends of the bosses'i-n the sockets formed in the blades all shearing strains are relieved from the bolts 86 and are exerted against the bosses which are a permanent part of the rotor. This 1s also an important feature as it permits use of shims 41 between the ibottoms of the sockets and. the ends of the bosses to space the blades therefrom in compensating for wear of the blades withrelation .to a stationary blade 42 that is attached to an angle member 43 extending across the lower edge of the inlet opening 18, the angle being mounted on an angle '44 attached to the outer face of the plate 2' at a point below the bearing 20.

Formed in the trailing edge of each arm 26 'and27 of the rotor is an ear 4 5 having an aperture '46 to mounthammer elements later described. The ears 45 are positioned substantially midway of the .depth of the rotor chamber and are therefore ofiset from the arms by angle-shaped 'web portions 47 extending laterally to the faces of'the arms opposite to the cutter knives.

The hammer elements preferably comprise flat paddle-like blades 48 of suflicient width to extend across the depth .of the rotor chamber and have fiat forward faces 49 for engaging the material to be reduced; The ends oftheblades terminate in'close proximity with the inner peripheral surfaces. oftlie rotor chamber and cooperate therewith in crushing thematerial' being re-;

duced and for propelling it through the perforated screen. The rear faces of the hammers have spaced ribs 50 and 51 terminating in ears 52' having aligned openings 53 by which the hammers are pivotally 'mounted on bolts 54 extending through the openi'ngs 46 formed in'the ears 45 above described.

' y thus pivotally mounting the hammers they are adapted to swing radially at the ends of the arms to permit passage of solid ed on theroto'r.

through the inlet opening and discharge the reduced material through the screen for elevating it through the stack so that no blowor is required to move the material through the grinder. to supplement the fanning action of the hammers by blades 57 and 58 which may be To operate the grinder constructedand assembled as described, the pulley is belted to a suitable source of power so that the rotor is operated at'the proper speed. The material to be reduced is fed through the inlet opening and is out into small pieces which are sucked into the' rotor chamber and reduced by impact and grinding ac- 'tion of the hammers until the particles are of sufficient sizeto be blown through the screen. The grain on passing throughthe screen is delivered through the conduit 15 by the fanning action of the hammersfisupplemented by the fanblades 57 and 58.

What I claim'and desire-to secure by Let ters Patent is: i

1. In a grinding mill including a casing forming a cylindrical rotor chamber having aside inlet, a knife bar extending across the lower edge ofthe inlet, a rotor in the chain However, it may be desirable formed integrally with the rotor and pro- .7

ject laterally from the sides-of the arms op posite to the cutter bladesher comprising radially opposed arms operj able in close relation to said knife bar and of a length to extend substantially across the width of said opening, knife blades having their opposite ends fixed to the side faces of said arms and provided with cutting edges projecting below the advance edges of the arms to cooperate with the knife bar, ears formed on said arms and offset" laterally fromthe' side of the arms opposite to said knife blades andarrangedto move in a cir-' cular path substantially midway of the width of said chamber, and hammer me'mbers pivotally'connected witlrsaid-ears to reduce material cut 'by said knives;- i

2. In a grinding mill'including a casing forming a cylindrical rotor chamber having a side inlet, a knife bar extending acrossthe lower edge of the inlet, a rotor in the chain ber comp-rising radially opposed arms oper- I able in close relation to said knife bar and of a length to extend substantially across the width of said opening, knife blades having their opposite ends fixed to the side faces of said arms and provided with cutting edges projecting below ,the advance edges of the arms to cooperate with the knifebar, ears formed on said arms and offset laterally from the side of the armsopposite to, said knife blades and arranged to movein'a oi-rcular path substantially midway of the width of said chamber, hammer member's pivotally connected w1th said ears to reduce material cut by said knives, and fan" blades projecting radially and laterally from said izs arms opposite to said knives for supplementing a fanning action of the hammer members and toreinforce said arms against strains produced by offsetting said pivotal mounting of the hammer members.

3. In a grinding mill including a casing forminga rotor chamber and having a side inlet, a fixed knife bar extending across the lower edge of the inlet, a rotor in the chamber comprising radially opposed arms operable in close relation to said knife bar and of a length to extend substantially across the Width of said opening, knife blades having their opposite ends fixed to the side faces of said arms and provided with cutting edges located adjacent the advance edges of the arms to cooperate with the fixed knife bar, ears formed on said arms and offset laterally from the side thereof opposite to said knife blade, hammer members pivotally connectedwith said ears to reduce material cut by said knives, lugs projecting from opposite sides of the ears to limit pivotal movement of the hammer members, and fan blades projecting radially and laterally from said arms opposite to said knives for supplementing fanning action of the hammer members and to reinforce said arms against strains produced by offsetting said pivotal mounting of the hammer members.

In testimony whereof I afiix my signature.

OTTO N. GREDELL. 

